Methods for progress tracking

ABSTRACT

The present invention provides systems and methods of managing planning and delivery of an orthodontic treatment using planning tools, treatment guidelines, instructions and appointment planning tools customized to the individual patient being treated, as well as tools and methods for tracking delivery and patient progression through an orthodontic treatment plan.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.12/129,578, filed May 29, 2008, which is a continuation-in-part of U.S.application Ser. No. 11/760,701, entitled “Treatment Planning andProgress Tracking Systems and Methods,” filed on Jun. 8, 2007, nowabandoned, which is related to U.S. application Ser. No. 11/760,689,entitled “Systems And Method for Management And Delivery Of OrthodonticTreatment,” filed on Jun. 8, 2007, now U.S. Pat. No. 9,060,829, issuedon Jun. 23, 2015; U.S. application Ser. No. 11/760,705, entitled“Treatment Progress Tracking And Recalibration,” filed on Jun. 8, 2007,now U.S. Pat. No. 8,562,338, issued on Oct. 22, 2013; and U.S.application Ser. No. 11/760,612, entitled “System And Method ForDetecting Deviations During The Course Of An Orthodontic Treatment ToGradually Reposition Teeth,” filed on Jun. 8, 2007, now U.S. Pat. No.8,075,306, issued on Dec. 13, 2011; the full disclosures of which areincorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates generally to the field of orthodontics,and more particularly to systems and methods of managing planning anddelivery of an orthodontic treatment using planning tools, treatmentguidelines, instructions and appointment planning tools customized tothe individual patient being treated, as well as tools and methods fortracking delivery and patient progression through an orthodontictreatment plan.

An objective of orthodontics is to move a patient's teeth to positionswhere function and/or aesthetics are optimized. Traditionally,appliances such as braces are applied to the patient's teeth by anorthodontist or dentist and the set of braces exerts continual force onthe teeth and gradually urges them toward their intended positions. Overtime and with a series of clinical visits and adjustments to the braces,the practitioner adjusts the appliances to move the teeth toward theirfinal destination.

More recently, alternatives to conventional orthodontic treatment withtraditional affixed appliances (e.g., braces) have become available. Forexample, systems including a series of preformed aligners have becomecommercially available from Align Technology, Inc., Santa Clara, Calif.,under the tradename Invisalign® System. The Invisalign® System includesdesigning and/or fabricating multiple, and sometimes all, of thealigners to be worn by the patient before the aligners are administeredto the patient and used to reposition the teeth (e.g., at the outset oftreatment). Often, designing and planning a customized treatment for apatient makes use of computer-based 3-dimensional planning/design tools,such as ClinCheck® from Align Technology, Inc. The design of thealigners can rely on computer modeling of a series of planned successivetooth arrangements, and the individual aligners are designed to be wornover the teeth and elastically reposition the teeth to each of theplanned tooth arrangements.

Recent advances in orthodontic treatment, including availability of thetreatment systems discussed above, have made orthodontic treatmentoptions available to a wide variety of patients and dentalpractitioners. Unfortunately, barriers to more wide-spread use of suchtreatment options still exist, thereby preventing both patients anddental practitioners from access to orthodontic treatment technologythey desire. One such barrier includes more wide-spread use oforthodontic treatment technology to dental practitioners with limitedexperience in orthodontics. For example, many general dentalpractitioners with limited knowledge or exposure to orthodontics may beinterested in learning orthodontic techniques and providing suchtreatment to patients, but may lack confidence in their abilities toeffectively deliver treatment and/or achieve predictable outcomes.Furthermore, while patient treatment and tooth movements can be plannedprospectively, in some cases orthodontic treatment can deviate from theplanned treatment or stages, which can be challenging to practitionersof any experience level and can lead to variability in treatment outcomeand, in many cases, decreased treatment efficacy. Deviations can arisefor numerous reasons, and can include biological variations, poorpatient compliance, and/or factors related to biomechanical design. Inthe case of aligners, continued treatment with previously designedand/or fabricated aligners can be difficult or impossible where apatient's teeth deviate substantially from the planned treatment course.For example, subsequent aligners may no longer fit the patient's teethonce treatment progression has deviated from the planned course.

Accordingly, improved methods and techniques are needed for facilitatingorthodontic practice among a wide range of practitioners, includingthose with limited experience in orthodontics as well as experiencedpractitioners desiring more guidance particularly for complex cases.Furthermore, because detecting a deviation from planned treatment mosttypically relies on visual inspection of the patient's teeth orobservation of appliances no longer fitting, treatment can sometimesprogresses significantly off track by the time a deviation is detected,thereby making any required corrective measures more difficult and/orsubstantial. Treatment planning an management systems that can provideearlier and better off track determinations, together with otherenhanced planning and management tools, would, therefore, be beneficial.

BRIEF SUMMARY OF THE INVENTION

The present invention provides systems and methods of managing planningand delivery of an orthodontic treatment using enhanced treatmentplanning options and features including appointment planning tools andguidelines, and treatment progress tracking features, where options canbe specifically customized to the individual patient being treated.Systems and methods of managing orthodontic treatment as disclosedherein can be included or incorporated in a variety of orthodontictreatment regimens including, for example, treatment according to theInvisalign® System. Treatment can be planned proactively or pre-plannedfor administration to a patient in a series of one or more phases, withat least some of the phases including a set of appliances that are wornsuccessively by the patient to reposition the teeth through pre-plannedarrangements and eventually toward a selected final arrangement. Plannedtreatment phases can include customized treatment guidelines tailored tothe particular treatment plan generated for the patient being treated,the guidelines being useful in helping to more effectively managedelivery and treatment of the patient according to the treatment plan.Additionally, progress tracking features can be incorporated into apre-planned treatment for monitoring and management of treatmentdelivery and progress, and to provide enhanced detection and feedback asto whether treatment is progressing as planned. Treatment plan optionscan be provided in a treatment plan individually or in a pre-selectedbundle or package of options, and may be provided based on an expresseddesired by the patient or practitioner or based on screening or caseassessments and resulting recommendations or suitable correspondingoptions.

Thus, in one aspect, the present invention includes methods and systemsof managing delivery of an orthodontic treatment plan. A method caninclude, for example, generating a case difficulty assessment based oninformation received, generating a treatment plan for a patient,providing customized set(s) of treatment guidelines, and trackingprogression of the patient's teeth along a treatment path or accordingto the treatment plan. In another example, a method can includereceiving information indicating a dental condition of a patient or atreatment goal, providing the practitioner with a selection of enhancedtreatment plan options including, for example, phased treatment deliver,appointment planning tools, and progress tracking features. A system caninclude, for example, a computer coupled to a server, the computercomprising a processor and a computer readable medium comprisinginstructions which, if executed, cause the computer to generate a caseassessment, generate a treatment plan for a patient, generate acustomized set of treatment guidelines, and generate progress trackinginformation, for example, a determination of whether an actualarrangement of the patient's teeth deviates from a planned tootharrangement.

For a fuller understanding of the nature and advantages of the presentinvention, reference should be made to the ensuing detailed descriptionand accompanying drawings. Other aspects, objects and advantages of theinvention will be apparent from the drawings and detailed descriptionthat follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing the anatomical relationship of the jaws of apatient.

FIG. 2A illustrates in more detail the patient's lower jaw and providesa general indication of how teeth may be moved according to anembodiment of the present invention.

FIG. 2B illustrates a single tooth from FIG. 2A and definesdetermination of tooth movement distance according to an embodiment ofthe present invention.

FIG. 2C illustrates the jaw of FIG. 2A together with an incrementalpositioning adjustment appliance according to an embodiment of thepresent invention.

FIG. 3A shows generating and administering treatment according to anembodiment of the present invention.

FIG. 3B is a block diagram illustrating a system according to anembodiment of the present invention.

FIG. 3C is a diagram of a process according to an embodiment of thepresent invention.

FIG. 4 illustrates generating a treatment plan according to anembodiment of the present invention.

FIG. 5 shows a user interface illustrating results of an assessment andadditional information, according to an embodiment of the presentinvention.

FIG. 6 illustrates a user interface graphical representation ofelectronically provided guidelines corresponding to a treatment planaccording to an embodiment of the present invention.

FIG. 7A illustrates a user interface graphical representation ofelectronically provided guidelines according to another embodiment ofthe present invention.

FIG. 7B illustrates a user interface graphical representation ofelectronically provided guidelines corresponding to a treatment planaccording to another embodiment of the present invention.

FIG. 8 illustrates a process including teeth matching according to oneembodiment of the present invention.

FIG. 9 shows a process including teeth matching according to anotherembodiment of the present invention.

FIG. 10 is a screen shot showing a graphical representation of athree-dimensional model of a patient's upper and lower jaws based on acurrent digital data set representing teeth in their current positions,according to an embodiment of the present invention.

FIG. 11 is a graphical representation of a three-dimensional model of aninitial match that can occur when the three dimensional model of digitaltranslated images are overlaid on three dimensional model of the CurrentTeeth Image, according to one embodiment of the present invention.

FIG. 12A through FIG. 12C show plurality of stages of teeth correctionand revision of treatment, according to several embodiments of thepresent invention.

FIG. 13 is a block diagram illustrating a system for generatingappliances in accordance with methods and processes of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides improved systems and methods of managingdeliver of an orthodontic treatment plan using proactive treatmentplanning and enhanced treatment planning tools including, for example,customized treatment guidelines and appointment planning tools, andtreatment progress monitoring and tracking techniques. Systems andmethods of the present invention can be included in a variety oforthodontic treatment regimens. For example, the progress tracking andrevised planning features can be optionally included and incorporatedinto other aspects of treatment according to the Invisalign® System.Treatment can be pre-planned for administering to a patient in a seriesof one or more phases, with at least some phases each including a set ofappliances that are worn successively by the patient to reposition theteeth through planned arrangements and eventually toward a selectedfinal arrangement. Enhanced treatment options (e.g., case assessment,appointment planning, progress tracking, etc.), according to the presentinvention, can be incorporated into the pre-planned treatment to providea more comprehensive system for treatment planning, monitoring andmanagement.

FIG. 1 shows a skull 10 with an upperjaw bone 22 and a lowerjaw bone 20.The lowerjaw bone 20 hinges at a joint 30 to the skull 10. The joint 30is called a temporal mandibular joint (TMJ). The upperjaw bone 22 isassociated with an upper jaw 101, while the lower jaw bone 20 isassociated with a lower jaw 100. A computer model of the jaws 100 and101 is generated, and a computer simulation models interactions amongthe teeth on the jaws 100 and 101. The computer simulation allows thesystem to focus on motions involving contacts between teeth mounted onthe jaws. The computer simulation allows the system to render realisticjaw movements that are physically correct when the jaws 100 and 101contact each other. The model of the jaw places the individual teeth ina treated position. Further, the model can be used to simulate jawmovements including protrusive motions, lateral motions, and “toothguided” motions where the path of the lower jaw 100 is guided by teethcontacts rather than by anatomical limits of the jaws 100 and 101.Motions are applied to one jaw, but may also be applied to both jaws.Based on the occlusion determination, the final position of the teethcan be ascertained.

Referring now to FIG. 2A, the lower jaw 100 includes a plurality ofteeth 102, for example, At least some of these teeth may be moved froman initial tooth arrangement to a final tooth arrangement. As a frame ofreference describing how a tooth may be moved, an arbitrary centerline(CL) may be drawn through the tooth 102. With reference to thiscenterline (CL), each tooth may-be moved in orthogonal directionsrepresented by axes 104, 106, and 108 (where 104 is the centerline). Thecenterline may be rotated about the axis 108 (root angulation) and theaxis 104 (torque) as indicated by arrows 110 and 112, respectively.Additionally, the tooth may be rotated about the centerline, asrepresented by an arrow 112. Thus, all possible free-form motions of thetooth can be performed.

FIG. 2B shows how the magnitude of any tooth movement may be defined interms of a maximum linear translation of any point P on a tooth 102.Each point P1 will undergo a cumulative translation as that tooth ismoved in any of the orthogonal or rotational directions defined in FIG.2A. That is, while the point will usually follow a nonlinear path, thereis a linear distance between any point in the tooth when determined atany two times during the treatment. Thus, an arbitrary point P1 may infact undergo a true side-to-side translation as indicated by arrow d1,while a second arbitration point P2 may travel along an accurate path,resulting in a final translation d2. Many aspects of the presentinvention are defined in terms of the maximum permissible movement of apoint P1 induced on any particular tooth. Such maximum tooth movement,in turn, is defined as the maximum linear translation of that point P1on the tooth that undergoes the maximum movement for that tooth in anytreatment step.

FIG. 2C shows one adjustment appliance 111 which is worn by the patientin order to achieve an incremental repositioning of individual teeth inthe jaw as described generally above. The appliance can include a shell(e.g., polymeric shell) having teeth-receiving cavities that receive andresiliently reposition the teeth. Such appliances, including thoseutilized in the Invisalign® System, are described in numerous patentsand patent applications assigned to Align Technology, Inc. including,for example in U.S. Pat. Nos. 6,450,807, and 5,975,893, as well as onthe company's website, which is accessible on the World Wide Web (see,e.g., the url “www.aligntech.com”).

As set forth in the prior applications, each appliance may be configuredso that its tooth-receiving cavity has a geometry corresponding to anintermediate or final tooth arrangement intended for the appliance. Thepatient's teeth are progressively repositioned from their initial tootharrangement to a final tooth arrangement by placing a series ofincremental position adjustment appliances over the patient's teeth. Theappliances can be generated all at the same stage or in sets or batches,e.g., at the beginning of a stage of the treatment, and the patientwears each appliance until the pressure of each appliance on the teethhas resulted in the maximum allowable tooth movement for that givenstage. A plurality of different appliances (e.g., set) can be designedand even fabricated prior to the patient wearing any appliance of theplurality. At that point, the patient replaces the current appliancewith the next appliance in the series until no more appliances remain.The appliances are generally not affixed to the teeth and the patientmay place and replace the appliances at any time during the procedure.The final appliance or several appliances in the series may have ageometry or geometries selected to overcorrect the tooth arrangement,i.e., have a geometry which would (if fully achieved) move individualteeth beyond the tooth arrangement which has been selected as the“final.” Such over-correction may be desirable in order to offsetpotential relapse after the repositioning method has been terminated,i.e., to permit movement of individual teeth back toward theirpre-corrected positions. Over-correction may also be beneficial to speedthe rate of correction, i.e., by having an appliance with a geometrythat is positioned beyond a desired intermediate or final position, theindividual teeth will be shifted toward the position at a greater rate.In such cases, the use of an appliance can be terminated before theteeth reach the positions defined by the appliance.

Referring to FIG. 3A, a process 200 according to the present inventionis illustrated. Individual aspects of the process are discussed infurther detail below. The process includes receiving informationregarding the orthodontic condition of the patient and/or treatmentinformation (Step 202), generating an assessment of the case (Step 204),and generating a treatment plan for repositioning a patient's teeth(Step 206). Briefly, a patient/treatment information will includeobtaining data comprising an initial arrangement of the patient's teeth,which typically includes obtaining an impression or scan of thepatient's teeth prior to the onset of treatment and can further includeidentification of one or more treatment goals selected by thepractitioner and/or patient. A case assessment can be generated (Step204) so as to assess the complexity or difficulty of moving theparticular patient's teeth in general or specifically corresponding toidentified treatment goals, and may further include practitionerexperience and/or comfort level in administering the desired orthodontictreatment. In some cases, however, the assessment can include simplyidentifying particular treatment options (e.g., appointment planning,progress tracking, etc.) that are of interest to the patient and/orpractitioner. The information and/or corresponding treatment plan willinclude identifying a final or target arrangement of the patient's teeththat is desired, as well as a plurality of planned successive orintermediary tooth arrangements for moving the teeth along a treatmentpath from the initial arrangement toward the selected final or targetarrangement.

The process further includes generating customized treatment guidelines(Step 208). The treatment plan typically includes multiple phases oftreatment, with a customized set of treatment guidelines generated thatcorrespond to a phase of the treatment plan. The guidelines will includedetailed information on timing and/or content (e.g., specific tasks) tobe completed during a given phase of treatment, and will be ofsufficient detail to guide a practitioner, including a less experiencedpractitioner or practitioner relatively new to the particularorthodontic treatment process, through the phase of treatment. Since theguidelines are designed to specifically correspond to the treatment planand provide guidelines on activities specifically identified in thetreatment information and/or generated treatment plan, the guidelinesare said to be customized. The customized treatment guidelines are thenprovided to the practitioner so as to help instruct the practitioner ashow to deliver a given phase of treatment. As set forth above,appliances can be generated based on the planned arrangements and willbe provided to the practitioner and ultimately administered to thepatient (Step 210). The appliances are typically provided and/oradministered in sets or batches of appliances, such as 2, 3, 4, 5, 6, 7,8, 9, or more appliances, but are not limited to any particularadministrative scheme. Appliances can be provided to the practitionerconcurrently with a given set of treatment guidelines, or appliances andguidelines can be provided separately.

After the treatment according to the plan begins and followingadministration of appliances to the patient, treatment progresstracking, e.g., by teeth matching, is done to assess a current andactual arrangement of the patient's teeth compared to a plannedarrangement (Step 212). If the patient's teeth are determined to be“on-track” and progressing according to the treatment plan, thentreatment progresses as planned and treatment progresses to a next stageof treatment (Step 214). If the patient's teeth have substantiallyreached the initially planned final arrangement, then treatmentprogresses to the final stages of treatment (Step 214). Where thepatient's teeth are determined to be tracking according to the treatmentplan, but have not yet reached the final arrangement, the next set ofappliances can be administered to the patient. If, on the other hand,the patient's teeth are determined at the progress tracking step (Step212) not to be tracking with the treatment plan, then treatment ischaracterized as “off-track” and an assessment is made as to how furthertreatment of the patient will proceed. Typically, a revised treatmentplan will be generated (Step 216), and may be selected, for example, toreposition the teeth from the current position to a final position,which may be the same destination as the initially determined finalposition according to the initial treatment plan.

FIG. 3B is a block diagram illustrating a network based treatmentplanning and management system according to one embodiment of thepresent invention. Referring to FIG. 3B, the system 250 includes a datanetwork 252 and a server terminal 254 operatively coupled to the network252. One or more client terminals 256 can be included and operativelycoupled to the network 252. Client terminals 256 can include, forexample, a computer terminal (e.g., personal computer) and the serverterminal 254 can be configured to communicate with the one or moreclient terminals 256 over the network 252 to both transmit and receiveinformation related to patient treatment as described herein, includinginitial patient treatment information, assessment data, appointmentplanning data, progress tracking data, etc. The server terminal 254 willbe accessible by a third party participant in the process of theinvention, in addition to the practitioner, that can at least partiallyparticipate in one or more of steps of the process (e.g., assessment,treatment plan and/or guideline generation, progress tracking, appliancedesign and/or manufacture, etc.). Systems can optionally includenon-network based systems, including computers and software packagesdesigned to at least partially operate independent of a data network andin which various steps of the currently described methods can beaccomplished in an automated fashion at a remote location (e.g.,practitioner's office).

FIG. 3C is a flow diagram illustrating a process according to oneembodiment of the present invention. The process 260 includes a seriesof steps according to an overall treatment of a patient. The process 260includes submitting information regarding the patient and can includeinformation indicative a dental condition of the patient and/or one ormore treatment goals (Step 262). The information can be submitted via anetwork based system and can include directions, forms or other guidancefor providing information to a third party (e.g., treatment planningparty, appliance designer/manufacturer, etc.). Information can be storedin a database that can optionally be accessible for review (e.g., by thepractitioner) (Step 264). Next, information submitted can be reviewed bya third party for case assessment and a treatment plan generated, whichcan be reviewed by the treating practitioner or patient, for example,and accepted or modified (Step 266). Appliances are then generated andprovided to the practitioner, and are provided together with customizedappointment planning tools/guidelines, and one or more kits for progresstracking (Step 268). Treatment according to the treatment plan is thenadministered to the patient in a series of one or more treatment phases,with each phase including a set of appliances and correspondingcustomized appointment and treatment guidelines (Step 270). Treatmentprogress tracking can be performed to determine whether treatment isprogressing as planned and can include, for example, submitting (e.g.,electronic transmission, shipping, etc.) progress information such astreatment notes and observations, scans, photos, impressions, and thelike for progress tracking analysis (Step 272). A next batch ofappliances can be sent to the practitioner (Step 274) and, depending onthe results of the progress tracking analysis, can be the next set ofappliances in the original treatment phase or can be provided accordingto a revised treatment phase. Treatment according to the next phase ofthe plan, including the appliances received in Step 274, is thenadministered to the patient (Step 276). Treatment then either progressesto the final stages of treatment if the desired position of the teeth isachieved or treatment progresses according to a treatment plan.

FIG. 4 illustrates the general flow of an exemplary process 300 fordefining and generating a treatment plan, including repositioningappliances for orthodontic treatment of a patient. The process 300includes the methods, and is suitable for the apparatus, of the presentinvention, as will be described. The steps of the process can beimplemented as computer program modules for execution on one or morecomputer systems.

As an initial step, a mold or a scan of patient's teeth or mouth tissueis acquired (Step 302). This generally involves taking casts of thepatient's teeth and gums, and may in addition or alternately involvetaking wax bites, direct contact scanning, x-ray imaging, tomographicimaging, sonographic imaging, and other techniques for obtaininginformation about the position and structure of the teeth, jaws, gumsand other orthodontically relevant tissue. From the data so obtained, adigital data set is derived that represents an initial (e.g.,pretreatment) arrangement of the patient's teeth and other tissues.

The initial digital data set, which may include both raw data fromscanning operations and data representing surface models derived fromthe raw data, is processed to segment the tissue constituents from eachother (Step 304), including defining discrete dental objects. Forexample, data structures that digitally represent individual and/orsections of tooth crowns can be produced. In some embodiments, digitalmodels of entire teeth are produced, including measured or extrapolatedhidden surfaces and root structures.

Desired final position of the teeth, or tooth positions that are desiredand/or intended end result of orthodontic treatment, can be received,e.g., from a clinician in the form of a descriptive prescription, can becalculated using basic orthodontic prescriptions (e.g. Roth, Andrews,Ricketts, etc.), or can be extrapolated computationally from a clinicalprescription (Step 306). With a specification of the desired finalpositions of the teeth and a digital representation of the teeththemselves, the final position and surface geometry of each tooth can bespecified (Step 308) to form a complete model of the teeth at thedesired end of treatment. The result of this step is a set of digitaldata structures that represents a desired and/or orthodontically correctrepositioning of the modeled teeth relative to presumed-stable tissue.The teeth and surrounding tissue are both represented as digital data.

Having both a beginning position and a final target position for eachtooth, the process next defines a treatment path or tooth path for themotion of each tooth (Step 310). This includes defining a plurality ofplanned successive tooth arrangements for moving teeth along a treatmentpath from an initial arrangement to a selected final arrangement. In oneembodiment, the tooth paths are optimized in the aggregate so that theteeth are moved in the most efficient and clinically acceptable fashionto bring the teeth from their initial positions to their desired finalpositions.

At various stages of the process, the process can include interactionwith a clinician responsible for the treatment of the patient (Step312). Clinician interaction can be implemented using a client processprogrammed to receive tooth positions and models, as well as pathinformation from a server computer or process in which other steps ofprocess 300 are implemented. The client process is advantageouslyprogrammed to allow the clinician to display an animation of thepositions and paths and to allow the clinician to reset the finalpositions of one or more of the teeth and to specify constraints to beapplied to the segmented paths.

The tooth paths and associated tooth position data are used to calculateclinically acceptable appliance configurations (or successive changes inappliance configuration) that will move the teeth on the definedtreatment path in the steps specified (Step 314). Each applianceconfiguration corresponds to a planned successive arrangement of theteeth, and represents a step along the treatment path for the patient.The steps are defined and calculated so that each discrete position canfollow by straight-line tooth movement or simple rotation from the toothpositions achieved by the preceding discrete step and so that the amountof repositioning required at each step involves an orthodonticallyacceptable amount of force on the patient's dentition. As with othersteps, this calculation step can include interactions with the clinician(Step 312).

Having calculated appliance definitions, the process 300 can proceed tothe manufacturing step (Step 316) in which appliances defined by theprocess are manufactured, or electronic or printed information isproduced that can be used by a manual or automated process to defineappliance configurations or changes to appliance configurations.Appliances according to the treatment plan can be produced in entirety,such that each of the appliances are manufactured (e.g., prior totreatment), or can be manufactured in sets or batches. For example, insome cases in might be appropriate to manufacture an initial set ofappliances at the outset of treatment with the intention ofmanufacturing additional sets of appliances (e.g., second, third,fourth, etc.) after treatment has begun (e.g., as discussed furtherherein). For example, a first set of appliances can be manufactured andadministered to a patient. Following administration, it may be desirableto track the progression of the patient's teeth along the treatment pathbefore manufacturing and/or administering subsequent set(s) ofappliances.

Generating and/or analyzing digital treatment plans, as discussedherein, can include, for example, use of 3-dimensional orthodontictreatment planning tools such as ClinCheck from Align Technology, Inc.or other software available from eModels and OrthoCAD, among others.These technologies allow the clinician to use the actual patient'sdentition as a starting point for customizing the treatment plan. TheClinCheck technology uses a patient-specific digital model to plot atreatment plan, and then uses a processed (e.g., segmented) scan of theachieved treatment outcome to assess the degree of success of theoutcome as compared to the original digital treatment plan as, asdiscussed in U.S. Pat. Nos. 7,156,661 and 7,077,647 (see also, below).

Case Assessment

As set forth above, a case assessment can be generated so as tocharacterize the desired or appropriate treatment, including assessingor characterizing the complexity or difficulty in achieving a giventreatment, or conducting a preliminary analysis of the treatmentparameters (e.g., goals) for a determination of certain treatmentoptions that may be desired or available (e.g., customized guidelines,progress tracking features, etc.). Users can receive information todetermine whether a patient's orthodontic conditions qualify for aparticular treatment and further can obtain information associated withthe treatment such as treatment difficulty, the level of skillsnecessary or recommended to perform the proposed treatment, anticipatedtreatment duration period, associated costs, and the like. In oneembodiment, the assessment can include generating a manual visual aid ora computerized visual guide interface system. Additionally, in thecomputerized visual guide interface system, there are provided one ormore databases which have stored therein an index of statisticalinformation, computational algorithms, patient conditions, andassociated treatment information based upon, for example, desired one ormore treatment goals. Further description of certain assessment systemsand methods, including case difficulty assessments, see, for example,commonly owned U.S. application Ser. No. 11/580,536, entitled “Methodand System for Providing Dynamic Orthodontic Assessment and TreatmentProfiles,” filed on Oct. 13, 2006, which is incorporated herein byreference.

The assessment process generally involves receiving informationregarding the patient's orthodontic condition and/or treatment history,processing the received information including, e.g., using consultationor opinion (e.g., expert opinion), computational algorithms, clinicaldata and statistics, and/or historical case content, and the like, andtransmitting results of the assessment to a user of the system (e.g.,practitioner, clinician, patient, etc.). In this manner, a preliminarydetermination can be made whether a patient's orthodontic conditionsand/or the identified treatment goals qualify for treatment usingcertain appliances (e.g., Invisalign® System) generally, or morespecifically qualification a particular treatment package includingpre-selected treatment options. In some instances, an assessment caninclude simply receiving a practitioner's selection of desired enhancedtreatment plan options (e.g., appointment planning tools, progresstracking features, etc.). In addition, based on information received adetermination can be made regarding treatment parameters includingapproximate number of aligners necessary, approximate treatmentduration, difficulty of the treatment, associated level of real orperceived pain related to the treatment, and any other relevantcharacteristics or parameters that would be useful to the user of thesystem. Case assessment can occur at various points in a processaccording to the present invention, but will typically occur followingreceiving patient/treatment information and can occur before or aftergenerating an initial treatment plan.

FIG. 5 is an example user interface display for illustrating caseassessment information in accordance with one embodiment of the presentinvention. The user interface display 350 includes information for aparticular patient's orthodontic treatment as determined by thepatient's initial conditions and the desired or selected treatment goalsand/or options. The user interface 350 in one embodiment is configuredto display a simplified view of a treatment plan 352, and can provide ageneral treatment timeline showing certain treatment options, such asappointment planning tools and progress tracking. Displayed treatmentoptions can be interactive such that selection of a particular option inthe treatment plan view 352 generates more detailed display of steps ortasks in the selected option. The display 350 can further includeinformation 354 regarding the case assessment including, e.g.,qualification for a particular treatment service package, estimatedcosts and duration, as well as links for more detailed appointmentplanning tools. The display 350 can further include information 356 oroptions to modify treatment goals or a treatment plan, or option 358 toaccept and proceed with the proposed treatment plan.

Appointment Planning

As set forth above, once a treatment plan is in place the presentinvention includes generating customized treatment guidelines that canbe provided to the dental practitioner for facilitating administrationof treatment and improving desired treatment outcomes. Since thetreatment plan typically includes a series of one or more treatmentphases, a customized set of treatment guidelines will be generated andwill typically include a set of guidelines corresponding to each phaseof the treatment plan. Treatment guidelines are provided to thepractitioner for administration of treatment to the patient. Since aphase(s) of treatment can include a set of appliances to be administeredto the patient, treatment guidelines can be provided to the practitionerconcurrently with a set of appliances, or appliances and guidelines canbe provided separately. Guidelines can include, for example, hard copies(e.g., paper copies) printed and shipped to the practitioner, or caninclude one or more electronic copies transmitted to the practitionerover a network, for example, by email or by incorporation into othernetwork-based treatment planning tools (e.g., ClinCheck®).

As a treatment plan will typically include a series of one or moreappointments, guidelines will typically include one or more recommendedpatient/practitioner appointments that may include suggested timing forthe appointments. Suggested timing can be specific and may moreparticularly identify a date or specific date range for scheduling oneor more appointments, or can be more generalized and for eachappointment may list a broader timing range (e.g., 1 week appointment, 2week, 3 week, etc.). Appointment timing can be identified to coincidewith another treatment event, such as administering an appliance or setof appliance, or wearing of an appliance(s) by the patient for a periodof time. Guidelines corresponding to a particular appointment caninclude a list of recommended tasks to be completed during thepractitioner's appointment with the patient. Non-exclusive examples ofgeneral tasks that may need to be performed at a given appointment caninclude appliance delivery and administration to the patient; toothmodifications such as extractions, interproximal reduction (IPR),periodontal evaluation, and the like; placement/removal ofattachment(s); auxiliary placement; general monitoring and compliance;treatment progress tracking; finishing appointment or finalization oftreatment (e.g., refinement evaluation or final impression and/or orderretainer); retainer administration to the patient; retainer maintenance;cleaning appointments; etc. Since the guidelines provided to thepractitioner will be specifically customized to the individual patient,the guidelines will not only include identification of the tasks to becompleted but will typically include specific details and/orinstructions, customized to the individual patient, that will help guidethe practitioner through the identified tasks during an appointment withthe patient. In some instances, the information provided in thecustomized guidelines can be further tailored to the practitioner toprovide the appropriate level of detail, content, and the like. Forexample, information provided to the practitioner, such as amount ofdetail in the identified tasks, can be selected based on the experiencelevel of the practitioner or preferences of the practitioner, e.g.,including preferences specified by the practitioner.

As set forth above, guidelines can include, for example, hard copies(e.g., paper copies) printed and shipped to the practitioner, or caninclude one or more electronic copies transmitted to the practitionerover a network. In addition to recommended appointments, recommendedtasks, and specific instructions or guidance on how tasks may becompleted, guidelines according to the present invention can includeadditional information and/or details that can further facilitate apractitioner in administering treatment to the patient, such as supportcontact information, direction to additional training materials, productordering information, and the like. For example, where guidelines areprovided electronically, such as on-line, additional materials caninclude one or more hyperlinks, such as JIT troubleshooting links,support links and/or numbers, e-mail links, order placement links, linksto ClinCheck® sharing modules, training modules or information, etc.

FIG. 6 shows a screen shot including a user interface 360 illustrating agraphical representation of electronically provided guidelinescorresponding to a treatment plan according to an embodiment of thepresent invention. A user can select a given appointment (example“Appointment 1” is illustrated) from an appointment menu 362 andcustomized set of treatment guidelines 364 are displayed correspondingto the selected appointment. The guidelines 364 can include a generaldescription of the selected appointment (e.g., “purpose”) so as tocommunicate to the practitioner general goals to be accomplished at theappointment. The guidelines 364 can further include a list of specifictasks to be completed. Specific tasks can be selected by thepractitioner for further viewing of more specific details, such as byselecting a drop down menu that provides more detailed and specificinstructions to guide the practitioner through administration of thetasks. For a given appointment, a graphical representation of thepatient's projected tooth position 366 at a given appointment or timecan be provided and incorporated into the interface for delivering theguidelines or task instructions. For example, as shown, specificidentification 368 of interproximal reduction areas may be shown and cancontain details on the reduction to be performed. Attachment locations365, 367 can also be illustrated on the representation 366 to facilitatetreatment administration. Additional views 369 (e.g., thumbnail views)of the patients teeth can also be provided for selection by thepractitioner. Providing the guidelines and instructions along with suchgraphical illustrations can advantageously help to more effectivelycommunicate task instructions to the practitioner at the appropriatepoint in the treatment and more effectively manage treatment.

FIG. 7A shows a screen shot 500 illustrating a graphical representationof electronically provided guidelines according to another embodiment ofthe present invention. As above, a user can select a given appointment(e.g., “Appointment 1”, “Appointment 2”, etc.) from an appointment menu502 (e.g., appointment menu bar) for viewing of information includingcustomized guidelines corresponding to the selected appointment.Additionally, the appointment menu 502 can include an option to selectan overview or general information on the treatment plan in general,which can be graphically represented as a treatment plan overview tab504 in the menu 502. Selection of the overview 504 can further displayoverview information 506 providing information on the treatment plan ingeneral. Information 506 can include, for example, a list of tasks to becompleted throughout the treatment (or portion thereof) of the patient.Specifically identified task may be linked to other files so as toprovide additional detailed information on a given task upon selection.As above, a graphical representation 508 of the patient's teeth can bepresented illustrating projected tooth positions at a given time orappointment.

FIG. 7B shows a user interface 370 illustrating a graphicalrepresentation of electronically provided guidelines corresponding to atreatment plan according to another embodiment of the present invention.Customized treatment guidelines 372 are shown provided according to thetreatment plan. As above, drop down options 374 are provided that allowthe practitioner to select a given task in order to view more detailedinstructions and information for guidance on how to administer the task.The practitioner can toggle between various appointments by using anappointment menu 376 (e.g., menu bar), where a given appointmentaccording to the treatment plan can be selected, thereby providing alist of corresponding tasks to be completed at the selected appointment.Additionally, a graphical representation 378 of the patient's projectedtooth positions at the given time or appointment can be displayed andmay include a view menu 390 for selecting different graphical views ofthe patients teeth. Additional animation and/or instructions can beincluded or incorporated into a graphical representation of thepatient's teeth to further communicate treatment guidelines and tasks.

Progress Tracking

In some cases, patients do not progress through treatment as expectedand/or planned and, therefore, tracking or monitoring the progress ofthe patient's treatment will be desired. For example, in some instancesa patient's progression along a treatment path can become “off-track” orwill deviate from an initial treatment plan, whereby an actual tootharrangement achieved by the patient will differ from the expected orplanned tooth arrangement, such as a planned tooth arrangementcorresponding to the shape of a particular appliance. A determinationthat the progression of a patient's teeth is deviating or not trackingwith the original treatment plan can be accomplished in a variety ofways. As set forth above, off-track deviations can be detected by visualand/or clinical inspection of the patient's teeth. For example, asubstantial off track deviation from the expected or planned treatmentmay become apparent when the patient tries to wear a next appliance in aseries. If the actual tooth arrangement substantially differs from theplanned arrangement of the teeth, the next appliance will typically notbe able to seat properly over the patient's teeth. Thus, an off-trackdeviation may become substantially visually apparent to a treatingprofessional, or even to the patient, upon visual or clinical inspectionof the teeth.

Detecting deviations from a planned treatment, however, can bedifficult, particularly for patients as well as certain dentalpractitioners, such as those with more limited experience inorthodontics, certain general dentist, technicians and the like.Additionally, deviations that have progressed to the point that they arevisually detectable clinically are often substantially off track withrespect to the planned treatment, and earlier means of off-trackdetection is often desired. Thus, detecting deviations from a treatmentplan can also be accomplished by comparing digital models of thepatients teeth, and can often detect deviations from a treatment planbefore the deviation becomes substantially apparent by visual orclinical inspection.

Methods and techniques for tracking and preserving the original finalposition in the treatment is generally referred to herein as “teethmatching” or “bite matching”. For example, bite matching techniquesdescribed herein can include matching teeth from the original image ofthe teeth or impression, to surface(s) of a new model of the teeth takenafter treatment has begun. An off-track determination can be followed by“re-setting” to the actual position of the teeth as defined by datarepresented in the progress scan, the original data of the teeth (i.e.,segmented models from initial treatment plan), thereby allowingpreservation of the initially selected final target position of theteeth. In other words, the original data set which contains with it, anestablished target arrangement, can be reused, by repositioning theteeth arrangement according to the positions of the (same) teethcaptured in the progress scan. In so doing, a new planned path to gofrom the current to the target can be recreated without having to changethe original target configuration. This method includes using bitematching techniques to allow the current aligner geometry to berecalibrated and reshaped according to the actual position of the teethin the progress scan. Using such bite matching techniques providessignificant advantages in terms of efficiency as there is no need tore-segment and process the new scan of the teeth, and in terms ofefficacy since the initial final arrangement is preserved, even if thepatient progresses off track.

Incorporating the inventive techniques and tracking methods describedherein in managing delivery/modification would provide variousadvantages, including earlier detection of treatment deviations,allowing earlier remedial measures to be taken, if necessary, to avoidundesirable treatment outcomes and preservation of initial treatmentgoals, thereby ultimately allowing for more effective treatment andbetter clinical outcomes. Furthermore, treatment efficiency and efficacycan be increased by better avoidance of inefficient/undesirabletreatment “detours”. Additionally, improved monitoring and tracking, asdescribed, is more objective and reliable, and less qualitative innature than the common practice of visually identifying off-trackprogress. As such, currently described inventive methods and techniquescan inspire more confidence in both patients and practitioners,including practitioners (e.g., general dentist) that may be lessexperienced with a given treatment method and/or less confident in theirabilities to clinically detect off-track progression, or moreexperienced practitioners who may desire more detailed monitoring, forexample, in cases involving more difficult or less predictablemovements.

An exemplary computer based teeth matching process according to anembodiment of the present invention is described with reference to FIG.8 . First, data from an earlier treatment plan is received (Step 402).Typically, data includes the initial data set or image data representingthe patient's teeth in the original, pre-treatment positions, theinitially identified final position, as well as planned intermediate orsuccessive arrangements selected for moving teeth along the initialtreatment path from the initial arrangement to the selected finalarrangement. Next, a current jaw impression or data including a digitalrepresentation of the teeth in their current positions, after treatmenthas begun, is received and loaded (Step 404). Data including plannedarrangements of the teeth are then compared to data including arepresentation of the patient's teeth in their current positions for aninitial determination of whether a match exists (Step 406). Next, thenew jaw data is segmented and positioned in the original coordinatesystem (Step 408). The process then compares the original jaw dataagainst the new jaw data (Step 410). Based on the comparison, theprocess generates an analysis report (Step 412), new/revised treatmentoptions or plans (Step 414), and/or allows visualization of any detecteddiscrepancy (Step 416). See also, e.g., U.S. Pat. Nos. 7,156,661 and7,077,647, for discussion of comparing actual position of the teethrelative to a planned or expected position using a processed (e.g.,segmented) scan of the teeth positions following initiation oftreatment.

In some instances, detecting a deviation from a treatment plan viacomparison between digital models of the patients teeth can includecomparing a current scan or image, which has not been segmented, of thepatients teeth in a position after treatment has begun to a previouslysegmented data set of the patients teeth at a current, past or futurestage. Use of an unsegmented, rather than segmented, digitalrepresentation of the current teeth positions may be desirable, forexample, in order to avoid resource and/or labor intensive processingsteps to transform the current unsegmented digital teeth model to asegmented digital teeth model. In addition, lower resolution or qualityscans or images can save cost and time if the necessary reference pointscan be identified on the unsegmented current scan or image.

FIG. 9 is a flow chart showing the steps of correcting deviations from aplanned course of treatment to gradually reposition teeth, according toone embodiment of the present disclosure. The process starts in step600, when current jaw data or “Current Teeth Image” is received. Thecurrent jaw data includes data representing an actual arrangement of thepatients teeth following administration of appliances according to theoriginal treatment plan. In step 602, the Current Teeth Image ispre-processed using a digital data tool (DDT) such that each tooth isassigned a Facial Axis of the Clinical Crown (FACC), i.e. a uniquecurrent identifier, with jaw characteristics set. Typically, accordingto the described embodiment, the Current Teeth Image does not need to besegmented, which saves a technician's time and hence overall cost.

In step 604, a Previously Segmented Teeth Model is selected, and isinput into a system of the present invention for analysis and comparisonwith the Current Teeth Image. The Previously Segmented Teeth Modelselected can include an Initially Segmented Teeth Model or a digitalmodel of the patient's teeth in their initial, pre-treatment positions,the initial final position according to the initial or previoustreatment plan (e.g., Prescribed Tooth Arrangement), or a plannedsuccessive tooth arrangement therebetween.

In step 606, the Previously Segmented Teeth Model and the Current TeethImage are compared. This step includes a sort of “rough match” of thesegmented model and the Current Teeth Image to identify correspondingfeatures of the two models that may be compared (Step 608). For example,an initial matching algorithm can be executed which matches uniquestarting identifiers (FACCs) of each tooth in the Previously SegmentedTeeth Model to the respective unique current identifiers (FACCs) of eachtooth in the Current Teeth Image. The images can be overlaid on eachother and the relative location of each tooth identified by its uniqueidentifier (or FACC) to determine if there are any mismatches in step608.

If any mismatches are found, an initial match has not occurred and themismatches are displayed in the form of an informational dialog thatprovides details of the mismatches, such as teeth numberingirregularities or missing FACCs. A mismatch can occur, for example, ifthere are any teeth numbering irregularities, such as the total numberof teeth in each model is not the same, or at least one tooth is missinga FACC. Mismatches may result, for example, where substantial dentalwork or reconstruction (e.g., tooth extraction, tooth reconstruction,filling, etc.) has occurred following the initial treatment plan orgeneration of Previously Segmented Teeth Model.

In Step 610, initial mismatch errors as identified above can be manuallyaccounted for in the process. For example, a technician can manuallyadjust or reposition each tooth with a mismatch using the PreviouslySegmented Teeth Model or adjusts the information relating to each toothwith a mismatch (e.g., accounting for an extracted tooth).

If no mismatches are generated in step 608, or where mismatches havebeen accounted for according to 610, then an initial match occurs andthe process moves to step 612. The initial match confirms that thetechnician is using the correct Previously Segmented Teeth Model and theCurrent Teeth Image, which provides a good starting point for executinga surface matching algorithm.

In step 612, more detailed matching and comparison between PreviouslySegmented Teeth Model and the Current Teeth Image occurs, which includesexecution a surface matching algorithm. The surface matching algorithmcan take a number of samples of each tooth in the Previously SegmentedTeeth Model and finds the closest corresponding sampling point on theCurrent Teeth Image. A grid is created on each tooth and the number ofsamples is randomly selected and then the grid is overlaid on theCurrent Teeth Image.

In step 614, any resulting errors from the surface matching algorithmare compared to predetermined tolerances to determine if the resultingerrors are less than the predetermined tolerance. Error tolerances canaccount for potential differences in the models being compared thatmight impair meaningful comparison, such as errors due to typicalvariance between different scans or impressions, surface differences orfluctuations, and the like. If the resulting errors are greater than thepre-determined tolerance, then in step 616, error statistics for thesurface matching algorithm are typically output to a display device andcan be further redirected to a technician for manual input or correctionas in step 610.

If the resulting errors are less than the pre-determined tolerance, instep 618, then matching and comparison of the Previously Segmented TeethModel and the Current Teeth Image proceeds for a determination whetherthe actual arrangement of the patient's teeth deviates from the plannedarrangement. In particular, a determination can be made as to whetherpositional differences exist, and to what degree, between the teeth intheir current positions compared to the expected or planned positions.Positional differences may indicate whether the patient's teeth areprogressing according to the treatment plan or if the patient's teethare substantially off track. Various clinical and/or positionalparameters can be examined and compared for a determination as towhether a patient's teeth are substantially on track or are deviatingfrom an expected arrangement according to the treatment plan. Forexample, positional parameters examined can include tooth rotation,extrusion, intrusion, angulation, inclination, and translation.Threshold values for differences in one or more positional parameterscan be selected as being indicative of a significant or substantialdifference in tooth position. Exemplary threshold values for variouspositional parameters, according to one embodiment of the invention arelisted in Table 1 below. Detecting positional differences above theselected threshold value(s) indicates that the actual arrangement of thepatients teeth substantially deviates from the planned arrangement towhich the comparison is made.

TABLE 1 OFF TRACK DEFINITION. The threshold difference values of aplanned position of teeth to actual positions selected as indicatingthat a patient's teeth have progressed substantially off-track.Difference Type Movement Actual/Planned Rotations Upper central incisors9 deg Upper lateral incisors 11 deg Lower incisors 11 deg Upper cuspids11 deg Lower cuspids 9.25 deg Upper Bicuspids 7.25 deg Lower FirstBicuspid 7.25 deg Lower Second Bicuspid 7.25 deg molars 6 deg ExtrusionAnterior 0.75 mm Posterior 0.75 mm Intrusion Anterior 0.75 mm Posterior0.75 mm Angulation Anterior 5.5 deg Posterior 3.7 deg InclinationAnterior 5.5 deg Posterior 3.7 deg Translation BL Anterior 0.7 mm BLPosterior Cuspids 0.9 mm MD Anterior 0.45 mm MD Cuspids 0.45 mm MDPosterior 0.5 mm

If the patient's teeth are determined to be on track by comparison ofthe teeth in their current positions with teeth in their expected orplanned positions, then treatment can progress according to the existingor original treatment plan (Step 620). For example, a patient determinedto be progressing on track can be administered one or more subsequentappliances according to the treatment plan, such as the next set ofappliances. Treatment can progress to the final stages and/or can reacha point in the treatment plan where bite matching is repeated for adetermination of whether the patient's teeth are progressing as plannedor if the teeth are off track. If the patient's teeth are determined offtrack and deviating from the planned arrangement, then treatmentaccording to the original treatment plan will be suspended. Typically, amodified or revised treatment plan will be generated where a patient'steeth are determined as being substantially off track (Step 622).Regardless of whether the patient's teeth are determined to be off trackor progressing according to the treatment plan, the process can generatea report or analysis of the results, and/or visualize the comparison,including any detected discrepancy (Step 624). Any such product can betransmitted, for example, to a technician or treating professional, tothe patient, or elsewhere.

FIG. 10 is a screen shot showing a graphical representation of athree-dimensional model of a patient's upper and lower jaws 640, 650generated from a Current Teeth Image. As described above, using adigital detailing tool (DDT), a technician pre-processes the CurrentTeeth Image by assigning and placing FACC's or unique currentidentifiers 74 on each tooth in the model. Unique current identifiersare landmarks on the teeth for the purposes of matching. Each FACC has anumber associated with it and that is the tooth number, so the sametooth from the Previously Segmented Teeth Models and the Current TeethImage should be in a similar location.

FIG. 11 is a graphical representation of a three-dimensional model of astarting match that can occur when a Previously Segmented Teeth Model isoverlaid on the Current Teeth Image, according to one embodiment of thepresent disclosure. The initial match provides a starting position forsubsequent surface matching so that a good match is achieved.

If the initial matching algorithm determines that one or more teeth aremismatched, the initial matching algorithm cannot complete the initialmatching satisfactorily because of teeth numbering irregularities ormissing FACCs. In this instance, the initial matching algorithm willgenerate an informational dialog giving details of the mismatchesallowing the technician to correct them and execute the initial matchingalgorithm again. Also shown in FIG. 8 are four attachments 660, 662,664, 666 that have been optionally added to four of the patient's teeth.

See also, e.g., U.S. application Ser. No. 11/760,612, entitled “Systemand Method for Detecting Deviations During the Course of an OrthodonticTreatment to Gradually Reposition Teeth,” filed on Jun. 8, 2007(Attorney Docket No. 018563-014900US), the full disclosure of which isincorporated herein by reference, for further discussion of comparing anunsegmented representation of an actual arrangement of a patients teethafter treatment has begun, to a previously segmented model of thepatient's teeth.

While the timing of the progress tracking steps described herein can beselected by the practitioner, typically at least general timing forconducting progress tracking measures of the present invention will beincorporated into the treatment plan and, therefore, will be pre-plannedor planned at about the beginning of treatment or early on in the courseof the patient's treatment (e.g., prior to the patient wearing a givenset of appliances so as to reposition the teeth). Thus, in oneembodiment of the invention, a treatment plan will include a prescribedtiming for the planned tracking steps. The prescribed timing can includea specifically recommended date or may include an increment of time(e.g., at treatment week 9, 10, 11, etc.), or can be based on the timingof other events of the treatment plan (e.g., after a patient wears a setof appliances).

Timing of progress tracking steps can be selected to occur based on asomewhat standardized treatment protocol or can be more particularlycustomized to an individual patient. More standardized protocols cantake into account certain population statistics, generalized clinicalexpectations, and/or physiological parameters that can be used togenerally predict rate of movement of a patient's teeth and the minimumlength of treatment time necessary for the patient's teeth to progressoff track if such progression is occurring. Clinical parameters caninclude, for example, root structure, including length, shape, andpositioning, as well as certain jaw characteristics such as jaw bonedensity, patient age, gender, ethnicity, medications/health historyprofile, dental history including prior treatment with orthodontics,type of orthodontic treatment plan (extraction vs. non-extraction), andthe like. Assuming a 2-week wear interval for each appliance, with amaximum tooth velocity of 0.25 mm/tooth per aligner, typically about 16to 20 weeks of repositioning treatment (8 to 10 appliances) is requiredbefore movement of the teeth is substantial enough to detect anon-compliant or off track movement of the teeth, if such off trackmovement is occurring, though more drastic movements can produce offtrack movement after only a few weeks.

As set forth above, timing of tracking measures can be selected based onthe particular movement(s) prescribed and/or characteristics of thepatient being treated and, therefore, are said to be customized to theparticular patient. For example, certain desired tooth movements in atreatment plan may be deemed either more unpredictable or at increasedrisk of moving off track and may require specifically timed tracking ormonitoring. Additionally, certain physiological or clinicalcharacteristics of the patient may be identified as indicating thatparticularly timed and/or frequency of tracking might be desired.Whether tracking is selected based on standardized protocols or morecustomized to the individual patient, tracking may or may not beselected to uniformly timed during the course of treatment. For example,a lower frequency of tracking measures may be desired or needed duringcertain portions or phases of treatment than others (e.g. spaceclosure). Regardless of whether tracking timing is customized or morestandardized, the selected timing will typically provide the additionaladvantage of efficiently planning tracking in the treatment plan tominimize unnecessary use of practitioner time and other resources.

Once a determination is made that the patient's actual arrangement ofteeth deviates from a planned arrangement and that the patient's teethare not progressing as expected/planned, a change or correction in thecourse of treatment can be selected, for example, by generating aninterim or modified treatment plan. Referring to FIGS. 12A-12C, revisedtreatment following determination that a patient's teeth are notprogressing on track is described. As set forth above, a treatment planincludes a plurality of planned successive tooth arrangements for movingteeth along a treatment path from an initial arrangement to a selectedfinal arrangement. The treatment plan, administration of sets ofappliances to a patient according to the planned arrangements, caninclude a plurality of phases (1 through 4) where at time=0, the initialtreatment plan begins. The initial treatment plan is illustrated by asolid line. Bite matching for a determination of whether a case isprogressing “on track” or “off track”, as described above (e.g., FIGS.8, 9 ), can take place at one or more of the phases or points along theadministration of treatment.

In particular, current tooth positions of the patient can be obtainedfrom the patient any one or more phases and compared to segmented modelsof the patient's teeth according to an earlier or original treatmentplan. Where teeth are determined to be deviating from the plannedtreatment plan or progressing “off track”, as illustrated by brokenlines, modification or revision of treatment plan can occur. In oneembodiment, a revised treatment plan can include restaging the patient'streatment from the determined actual position to the originallydetermined final position (FIG. 12A). Revised treatment path(illustrated by dashed lines) can proceed directly toward the initiallydetermined final position and need not attempt to redirect treatmentback onto the original treatment path. In this case, while partialoverlap/intersection of the revised treatment path with the originaltreatment path may occur, the revised treatment path will at leastpartially diverge from the initial treatment path and proceed directlytoward the initially determined final arrangement of the teeth. Such anapproach may be selected, for example, where retaining the initiallydetermined final position is desired. This approach also advantageouslypermits use of the originally processed and segmented data, therebyallowing avoidance of costly processing steps.

Alternatively, a revised treatment plan can include a more direct“mid-course correction”, in which the revised treatment plan includes amore direct path back toward the a planned arrangement of the initialtreatment plan, as illustrated in FIG. 12B. While this approach may makeuse of the originally planned final arrangement, the more primaryconcern in this example type of correction is redirecting treatment backto the original treatment path, rather than from the actual positionthat is similar but not necessarily exactly the original final position.In yet another embodiment, as illustrated in FIG. 12C, a revisedtreatment plan can include essentially “re-starting” treatment, andgenerating a new final arrangement of the teeth, for example, fromsegmenting and staging a new impression of the teeth, and directing thepatient's teeth from the actual arrangement to the newly determinedfinal arrangement of the teeth.

Methodologies and systems of the present invention as described hereincan include various techniques integrating and managing steps discussedabove such as progress tracking into orthodontic treatment. For example,as new information is obtained during progress tracking measures,various data management techniques can be employed to make use of newlyobtained data, manage existing data (e.g., data in initial treatmentplanning), and/or incorporate or seamlessly synchronize new informationinto treatment planning (e.g., revised treatment plan), staging of theteeth, system interface with treating professionals and/or patients, andthe like. Thus, in one embodiment, the present invention can includesynchronizing one or more aspects of a revised treatment plan so as toincorporate or integrate revised treatment with other aspects oftreatment planning. For example, the revised treatment plan or data canbe synchronized or integrated with expectations of a treatingprofessional or patient for more seamless integration of new informationand minimizing potential disruptions due to altered treatment.

In one embodiment, a treatment plan, initial or revised, can include aretention appliance or means to constrain for a period or hold in adesired or current position the patient's teeth against further movementfor a period of time, such as time required for progress matching to beaccomplished. Such constraint means can include, for example, agenerated one or more duplicate stages or appliances to be successivelyworn by the patient. Duplicate appliances can include two or more shellappliances having the same or substantially the same geometries withrespect to tooth receiving cavities. Where each appliance in a series isworn for a prescribed period of time, generating duplicate appliancescan be administered to the patient and coordinated with progresstracking steps. In this manner, time for progress tracking can beafforded and more seamlessly integrated with treatment, with minimaldisruption to the patient. Such constraint means or duplicate stagesfurther prevent tooth movement relapse or movement of the teeth while anon-track/off-track assessment is being made. The creation of duplicatestages, however, should be synchronized with downstream actions plannedto coincide with a particular treatment stage, such as planned toothmodification, treatment planning, and the like (e.g., interproximalreduction, dentition/appliance modeling, digital representations, etc.).

As discussed, an off-track assessment may prompt creation of the revisedtreatment plan. Revised treatment planning can include restaginginvolving manipulation of existing segmented digital models of thepatient's teeth, e.g., so as to reflect current positions and shapes.The use of the existing segmented digital models advantageously avoidsthe added effort and expense associated with segmenting the newlyacquired progress scan data. Before the newly acquired progress scandata is used to restage the planned treatment, however, it may benecessary to reset the spatial orientation between the upper and lowerjaws. Resetting of the spatial orientation may be necessary where theupper and lower jaws in the newly acquired progress scan data are indifferent coordinate systems than were used for the existing segmenteddigital models of the patient's teeth. This resetting can beaccomplished by retaining the matched overlay positions obtained duringthe previous teeth matching process, and using these retained positionsto orient the jaws (see above). Matching teeth/jaw in a new coordinatesystem can be used for modification/generation of visualizations orgraphical views of the teeth/jaws to be provided to a user (e.g.,treating professional, technician, etc.). In the absence of suchmodifications, visual differences may be noticeable to a user.Modification with a new coordinate system can be accomplished such thatvisual differences in views presented to a viewer are less noticeableand revised treatment planning is more seamlessly presented to the user.

Data generated from progress tracking can optionally be utilized forrevision or updating of a gingival margin or line in existing model(s).In one embodiment, the gingival line is updated based upon the currentpositions of the teeth by overlaying the current positions of the teethwith existing segmented models. An updated gingival line can be used todetermine the cut line of a shell appliance, which can be based on thegingival/tooth margin.

The newly acquired progress scan data can also be used to set stages,e.g., initial, final positions, for the teeth that used during treatmentplan revision or restaging process. For example, the current toothpositions obtained as a result of the progress tracking scan can be usedas the initial tooth positions. Determination of the final toothpositions used during the restaging process can be made in at severalways. In one approach, the final tooth positions are set to be the sameas the final tooth positions of the previous treatment plan, which maybe rendered obsolete following off-track determination. Another approachcan be used to set some of the final tooth positions equal to theirrespective current positions as indicated by the progress scan, andsetting the positions of the other teeth to be the same as the previousfinal positions discussed above. This later approach may be selected inthe case of individual teeth, such as molars, that were not targeted forrepositioning in the previous treatment plan, but did experience someunplanned movement. Such unplanned movement may occur as a result of themovement of other teeth in the dental arch. In the event of suchunplanned movement, it may be that the current positions of such teethare acceptable, or even preferred, so that there is not any real benefitto attempt to move these teeth from their current positions.

Segmented digital models used in the restaging processes can be updatedto more accurately reflect the patient's current teeth where new data isobtained in progress tracking steps. Updating may include, e.g.,accounting for changes in the external shape of the patient's teeth thatoccurred during the prior course of treatment. For example, in someinstances treatment may include removal of a portion or exterior profileof one or more of a patient's teeth, such as interproximal reduction(IPR), so as to allow sufficient clearance for the movement of the teethduring the course of orthodontic treatment. Besides IPR, there may beother changes that have been made to the patient's teeth (e.g., removedtooth, dental filling, crown, and the like) subsequent to when initialpatient scan or data was obtained and used to produce an initialtreatment plan, including segmented model(s) of the patient's teeth, butprior to when the progress scan data was obtained. As such, there may bedifferences that exist between the exterior shapes of teeth in theoriginal data as compared to the progress scan data. Accordingly,previously existing or initial data such as tooth shape in an existingsegmented model can be modified so as to reflect detected changes. Inthe case of IPR, the previously obtained tooth exterior shape can bevirtually trimmed to account for the actual trimming that occurred priorto the progress scan.

Data obtained from progress tracking steps can further be utilized inassessing why the case went off track. One way of using the datainvolves providing or generating a visualization in which the plannedpositions and the current positions are shown for comparison. In oneembodiment, a visualization can display the planned positionssequentially relative to the currently measured positions. Such avisualization can provide information to a viewer (e.g, technician,practitioner, etc.) for determination as to why off-track teeth havedeviated from their planned repositioning, and can provide someperspective as to the relative magnitude of the off-track positionaldeviations. The formulation of the revised treatment plan can then beaccomplished with increased insight into the reasons behind suchdeviations. Where a revised treatment plan is generated includingrestaging, a determination can be made as to the number of appliances toinclude in the next series/batch for delivery to the practitioner orpatient.

Progress tracking steps and/or revised treatment planning will typicallyrequire data management tasks or management of newly acquired and/orexisting data. In some instances, tasks can include discarding data thatis no longer relevant, such as data regarding previously planned stagingsuperseded by the revised staging, or treatment file notes that are nolonger applicable. During restaging for revised treatment planning,current teeth positions can be reset to an initial or starting position,and a plurality of planned tooth positions generated for teeth movingalong a revised treatment path and toward a desired position. In someinstances, at least a portion of the previously existing data isretained, e.g., retained target position(s), data useful fordetermination/visualization of off-track progression and/or causes, andthe like.

In some instances, revised treatment planning may contemplate orprescribe tooth modifications, such as use of tooth attachments duringtreatment. Where revised treatment planning includes use of newattachments, down-stream applications and users can be notified that anew attachment is required. Templates for positioning attachments on apatient's teeth can be built into treatment planning and scheduled forproduction and/or delivery to a treating professional. Where revisedtreatment plan requires the removal of an attachment, the treatingprofessional can be notified (e.g., inclusion in appointment planning)that removal of the attachment is required.

As noted, methods can include synchronizing newly acquired data orinformation, or aspects of revised treatment, with previously plannedtreatment so as to integrate revisions with expectations of the treatingprofessional and/or patient. Incorporation of progress scan data andsynchronization of revised treatment, for example, can include selectingan appliance order of use indicia (e.g., numbers, colors, symbols,arrangement, etc.) matching an indicia used previously in treatment,e.g., prior to a progress tracking step. For example, appliances mayinclude numeric indicia designating order of use. Appliances generatedaccording to a revised treatment plan or subsequent to a progresstracking step can be numbered to follow the indicia expected to followin sequence the last numbered appliance provided. In such a manner,treatment revision can be accomplished in a more seamless manner fromthe perspective of a patient and/or treating provisional and avoidpotential confusion as to prescribed appliance sequence.

FIG. 13 is a simplified block diagram of a data processing system 700that may be used in executing methods and processes described herein.The data processing system 700 typically includes at least one processor702 that communicates with a number of peripheral devices via bussubsystem 704. These peripheral devices typically include a storagesubsystem 706 (memory subsystem 708 and file storage subsystem 714), aset of user interface input and output devices 718, and an interface tooutside networks 716, including the public switched telephone network.This interface is shown schematically as “Modems and Network Interface”block 716, and is coupled to corresponding interface devices in otherdata processing systems via communication network interface 724. Dataprocessing system 700 can include, for example, one or more computers,such as a personal computer, workstation, mainframe, and the like.

The user interface input devices 718 are not limited to any particulardevice, and can typically include, for example, a keyboard, pointingdevice, mouse, scanner, interactive displays, etc. Similarly, varioususer interface output devices can be employed in a system of theinvention, and can include, for example, one or more of a printer,display (e.g., visual, non-visual) system/subsystem, controller,projection device, audio output, and the like.

Storage subsystem 706 maintains the basic required programming,including computer readable media having instructions (e.g., operatinginstructions, etc.), and data constructs. The program modules discussedherein are typically stored in storage subsystem 706. Storage subsystem706 typically comprises memory subsystem 708 and file storage subsystem714. Memory subsystem 708 typically includes a number of memories (e.g.,RAM 710, ROM 712, etc.) including computer readable memory for storageof fixed instructions, instructions and data during program execution,basic input/output system, etc. File storage subsystem 714 providespersistent (non-volatile) storage for program and data files, and caninclude one or more removable or fixed drives or media, hard disk,floppy disk, CD-ROM, DVD, optical drives, and the like. One or more ofthe storage systems, drives, etc may be located at a remote location,such coupled via a server on a network or via the Internet's World WideWeb. In this context, the term “bus subsystem” is used generically so asto include any mechanism for letting the various components andsubsystems communicate with each other as intended and can include avariety of suitable components/systems that would be known or recognizedas suitable for use therein. It will be recognized that variouscomponents of the system can be, but need not necessarily be at the samephysical location, but could be connected via various local-area orwide-area network media, transmission systems, etc.

Scanner 720 includes any means for obtaining an image of a patient'steeth (e.g., from casts 721), some of which have been described hereinabove, which can be obtained either from the patient or from treatingprofessional, such as an orthodontist, and includes means of providingthe image data/information to data processing system 700 for furtherprocessing. In some embodiments, scanner 720 may be located at alocation remote with respect to other components of the system and cancommunicate image data and/or information to data processing system 700,for example, via a network interface 724. Fabrication system 722fabricates dental appliances 723 based on a treatment plan, includingdata set information received from data processing system 700.Fabrication machine 722 can, for example, be located at a remotelocation and receive data set information from data processing system700 via network interface 724.

It is understood that the examples and embodiments described herein arefor illustrative purposes and that various modifications or changes inlight thereof will be suggested to persons skilled in the art and are tobe included within the spirit and purview of this application and thescope of the appended claims. Numerous different combinations arepossible, and such combinations are considered to be part of the presentinvention.

1-20. (canceled)
 21. A method comprising: generating a treatment plancomprising a plurality of digital models of successive tootharrangements configured to move a patient's teeth along a treatment pathfrom an initial arrangement toward a target arrangement; generatinginstructions configured to cause a fabrication machine to fabricate aset of shell appliances based at least in part on the plurality ofdigital models of the successive tooth arrangements, wherein the set ofshell appliances include at least one retention appliance thatduplicates teeth receiving cavity geometries of at least one other shellappliance; tracking progression of the patient's teeth along thetreatment path after commencing administration of the set of shellappliances to the patient, wherein the tracking is timed to correspondto the patient wearing the at least one retention appliance; and afterdetermining that the patient's teeth have deviated from the treatmentpath, generating a revised treatment plan configured to correct thedeviation.
 22. The method of claim 21, wherein tracking the progressionof the patient's teeth comprises comparing a digital model of a currentarrangement of the patient's teeth to at least one of the plurality ofdigital models of the successive tooth arrangements.
 23. The method ofclaim 21, wherein tracking the progression of the patient's teethcomprises determining a difference between a current position of atleast one tooth and a planned position of the at least one tooth. 24.The method of claim 23, wherein the patient's teeth are determined tohave deviated from the treatment path if the difference is greater thana threshold value.
 25. The method of claim 21, wherein the at least oneretention appliance has a first plurality of teeth receiving cavities,the at least one other shell appliance has a second plurality of teethreceiving cavities, and the first plurality of teeth receiving cavitieshave the same geometries as the second plurality of teeth receivingcavities.
 26. The method of claim 21, wherein the at least one retentionappliance is configured to maintain the patient's teeth in a desiredarrangement for a period of time.
 27. The method of claim 21, whereinthe at least one retention appliance comprises a plurality of retentionappliances.
 28. The method of claim 21, wherein generating the revisedtreatment plan comprises generating a plurality of revised tootharrangements configured to move the patient's teeth along a revisedtreatment path from a current arrangement to the target arrangement. 29.The method of claim 21, wherein generating the revised treatment plancomprises generating a plurality of revised tooth arrangementsconfigured to move the patient's teeth along a revised treatment pathfrom a current arrangement to a revised target arrangement.
 30. Themethod of claim 21, further comprising outputting a visualization of thedeviation.
 31. A method comprising: generating a plurality of digitalmodels of successive tooth arrangements configured to move a patient'steeth along a treatment path from an initial arrangement toward a targetarrangement; tracking progression of the patient's teeth along thetreatment path after commencing administration of a set of shellappliances to the patient, wherein the set of shell appliances arefabricated based at least in part on the plurality of digital models ofthe successive tooth arrangements, wherein the set of shell appliancesinclude at least one retention appliance that duplicates tooth receivingcavity geometries of at least one other shell appliance, and wherein thetracking occurs at a time corresponding to the patient wearing the atleast one retention appliance; after determining that the patient'steeth have deviated from the treatment path, generating at least onedigital model of a revised tooth arrangement configured to correct thedeviation; and generating instructions configured to cause a fabricationmachine to fabricate at least one additional orthodontic shellappliance, based at least in part on the at least one digital model ofthe revised tooth arrangement.
 32. The method of claim 31, whereintracking the progression of the patient's teeth comprises comparing adigital model of a current arrangement of the patient's teeth to atleast one of the plurality of digital models of the successive tootharrangements.
 33. The method of claim 31, wherein tracking theprogression of the patient's teeth comprises detecting a discrepancybetween a current arrangement of the patient's teeth and a plannedarrangement of the patient's teeth.
 34. The method of claim 33, furthercomprising outputting a visualization showing the discrepancy.
 35. Themethod of claim 31, wherein the at least one retention appliance has afirst plurality of teeth receiving cavities, the at least one othershell appliance has a second plurality of teeth receiving cavities, andthe first plurality of teeth receiving cavities have the same geometriesas the second plurality of teeth receiving cavities.
 36. The method ofclaim 31, wherein the at least one retention appliance is configured tomaintain the patient's teeth in a desired arrangement for a period oftime.
 37. The method of claim 31, wherein the at least one retentionappliance comprises a plurality of retention appliances.
 38. The methodof claim 31, wherein the at least one digital model of the revised tootharrangement is generated from a previously segmented digital model ofthe patient's teeth.
 39. The method of claim 38, further comprisingmanipulating the previously segmented digital model to reflect a currentarrangement of the patient's teeth.
 40. The method of claim 38, furthercomprising revising one or more of a gingival margin or a tooth shape inthe previously segmented digital model.